Brake mechanism



Oct. 22, 1.940. l R. T. WHITNEY 2,218,601

BRAKE MEHANIs'M Filed June 30, 1939 2 Sheets-Sheet l .fw 8 9 mini/T 'I I L v I I""` uw?, /8 o O 5o mi I 42 s 26 4 ATTORNEY Patented Oct. 22, 1940 UNITED STATES PATENT ori-ICE Westinghouse Air Brake Company, Wiim ding, Paf, a corporation oi' Pennsylvania Application June 30, 1939, Serial No. 282,005.

Z4 Claims.

'Ihis invention relates to brake mechanism and more particularly to the general type disclosed in the pending application of Carlton D. lStewart Serial No. 214,517, led June 18, 1938, now Patent No. 2,177,953, dated Oct. 31, 1939, which is assigned to the assignee of this application `and which embodies a plurality of brake elements arranged in clasp relation at opposite sides o'f a wheel and axle assembly and one or more additional brake elements disposed above said assembly and cooperative with said clasp arranged elements for braking said'assembly.

In the brake mechanism disclosed in the above referred to application all of the brake elements are connected to a relatively long, heavy beam which extends longitudinally of the truck frame. One end of this beamis pivotally connected to the truck frame while a spring acts on the opposite end to support the beam and thereby the several brake elements from the truck frame when said brake elements are in their release position.

The clasp arranged brake elements are so disposed as to engage the wheel and axle assembly below the horizontal center-line thereof so that when forced against said assembly, in eilecting an application of the brakes, said brake elements will be moved downwardly around-the assembly to a certain degree and in so moviing will rock the beam about its pivotal connection with the truck frame and thus pull the additional 'brake element or elements located above the assemblyv and carried by the beam into braking engagement with said assembly.

The additional brake element or elements then act through the beam to support the clasp arranged elements in braking relation with the wheel and axle assembly, while the beam acts to hold the several brake elements against turning with said assembly.

' The braking operation of the several brake elements above described is therefore entirely independent lof the truck frame except for the torque connection therewith for holding said elements against turning while braking, so that vertical movement of the truck frame relative to the wheel and axle assembly has substantially no eiiect upon the action of the brake mechanism, and conversely, the braking action of said mechanism has substantially no effect upon the springing of the truck frame.

In trucks such as are employed under modern railway vehicles having low centers of gravity there is little available space for the installation of brake mechanisms, and oncertain'trucks it might even be impossible to install a brake (Cl. 18S-56) mechanism which included a long heavy beam, such as above described. One object oi.' the present invention is therefore to provide a novel brake mechanism of the above general type in which the need for such a beam is obviated.

Since in the brake mechanism disclosed in the aforementioned Stewart application the ybrake element located above the wheel and axle assembly is carried by and movable with the truck. frame when said element is in its release position, it will be evident that the clearance space between said element and the wheel and axle assembly, when the element is' in its release position with respect to the truck frame, will vary with movement of the truck frame from a required degree in a fully loaded condition -to an excessive degree when the truck frame is in the ,condition assumed when the vehicle carried thereby is empty. Another object of the invention is therefore to provide a novel brake mechanism of the above general type in which the release position of the brake element located above the wheel and axle assembly is independent of vertical movement of the truck frame relative to said assembly, so as to thereby obviate the undesirable condition just described.

A more specic object of the invention is to provide a novel brake mechanism of the general type disclosed in the aforementioned Stewart application which-embodies the advantages thereof but in which the disadvantages above enumerated are obviated. f

Another object of the invention is the provision of an improved`brake mechanism oi.' the above general typeand support means therefor which is entirely independent of the truck frame so that at no time will the brake mechanism or frame have any material iniluence on each other.

Another object of the invention is to provide' an improved multi-shoe brake mechanism of the above general type which is supported from an .unsprung part of a truck when in its brake release condition and from the wheel and axle assembly when operating to brake said assembly.

A still further object of the invention is the provision of a novel brake mechanism such as above described which is resiliently supported from an unsprung portion of the truck, and therefore independently of the truck frame, when in its brake release condition, and from the wheel and axle assembly when operating to brake said assembly and which is therefore at all times substantially independent of the loaded condition of the truck and therefore independent vof the vertical position which the truck frame may assume at different times.

Other objects and advantages will be apparent from the following more detailed description of the invention.

In'the accompanying drawings Fig. 1 is a plan view, partly in section, of a portion of a railway vehicle truck and a novel brake mechanism embocbring one form of the invention; Fig. 2 is a side elevational view of same; Fig. 3 is a sectional view taken on the line 3 3 in Fig. 2; Figs. 4 and 5 are views similar respectively to Figs. 1 and 2 but illustrating another form of the invention; and Figs. 6 and '7 are sectional views taken respectively on the lines 6-3 and 1--1 in Fig. 5.

Description of the brake mechanism shown in Figs. 1 to 3 of the drawings The form of the invention illustratedL in Figs. 1 to 3 of the drawings is shown associated with the railway vehicle truck for the purpose of illustration, which truck mayl comprise the usual truck frame I and longitudinally spaced wheel and axle assemblies each of which Amay comprise an axle 3 and laterally spaced vwheels 4 secured in any desired manner to the axle 3 for rotation therewith.

'I'he truck frame I comprises side pieces 5 disposed between the wheels 4 and integrally connected together byV transversely extending end members 3 and transoms 1. The side 4pieces 5 are provided adjacent each wheel 4V with the usual spaced, depending pedestals 3 between which is slidably mounted va. journal bearing 9 journaled on the axle 3. "A spring I3 is interposed between each journal bearing 3 and side piece 5 for resiliently supporting the truck frame I.

Each wheel and axle assembly of the truck may be provided with two brake mechanisms and both of these brake mechanisms may be substantially identical to each otherand operate in the .same manner. In view of this and foi the sake of simplicity, only one such brake mechanism and the necessary portions of one wheel and axle assembly and of the truck frame are therefore shown in the drawings.

The brake mechanism shown in Pigs. 1 to 3 in the drawings comprises a plurality of friction brake elements I2, I3 and I4 arranged in circumferentially spaced relation with respect to each other around a rotatable member to be braked, which member in the present embodiment of the invention is preferably the wheel 4 of the truck. The brake elements I2 and I3 are arranged in clasp relation at opposite sides of the wheel 4 with the longitudinal centers of theirv braking faces disposed below the horizontal center-line of the wheel, while the brake element I4 is located above the wheel on the vertical center-line thereof. Y

Each oi' the brake elements I2, I3 and I4 may be oi' usual structure comprising 'a brake head I5 provided on its outer face with parallel supporting flanges I1 extending longitudinally thereof. A brake to the opposite face of each ofthe brake heads in operating alignment with the tread of the wheel 4 for frictionally engaging said tread to brake said wheel. y

A dead brake lever I 3` is disposed to work in the space between the ilanges vvI1 of the brake element I2 and is secured. intermediate its ends to said flanges by a pivotpin 13. I{['hev upper end of-this lever is pivotally connected by a pin 2|.to one end of a tension link'ZI the opposite end of yare rockably connected to shoe I3 is removably secured which is pivotally connected to a pin 22 secured in a bracket 23 projecting from the side piece 5 of the .truck frame. At the opposite side of the wheel 4 a live lever 24 is provided to operate between the flanges I1 of the brake element I3 and is pivotally connected intermediate its ends to said flanges by a pin 23. 'I'he lower ends of the dead and live levers I3 and 24 are operatively connected together by a. pair of spaced, parallel tie rods 23 disposed at opposite sides of the wheel 4.

'I'he brake element I4 located above the wheel 4 is pivotally connected by a pin 21 to one end of a rigid torque element 23 the opposite end of which is connected by a pin 23 to a bracket 33 projecting from the side piece l of the truck frame.

At each of the opposite sides of the wheel 4 there is provided a diagonally extending rigid bars 3I and 32 having their upper ends pivotally connected to the pin 21 secured to the brake element I4. The lower ends of the bars 3i at both sides of the wheel 4 pivot pin Il at the opposite sides of the flanges I1 of the brake element I2, while the lower ends of the bars 32 are similarly connected to the pivot pin 2l secured in the brake element I3.

A bracket 33 is interposed between the wheel 4 and side piece 3 of the truck frame. This bracket straddles the top of the journal bearing 3 outside of the side piece of the truck frame and is rigidly' connected to said bearing by bolts 34.

The bracket 33 is provided at each side of the journal bearing 3 with a portion 3l which extends parallel to the side piece I of the truck frame to a point beyond `the adjacent portion oi' the tread of wheel 4, at which point each of the portions 35 is bent outwardly over the tread of the wheel land is provided at its end with two arms 31 extending in a direction away from the wheel.

The arms 31 of the two bracket portions 3l are so spaced as to extend over a pair of oppositely disposed lugs 33 projecting from the opposite faesof anges I1 of the brake elements I2 and yI3 and in the end of each of said arms there is secured in any desired manner, as by hooking, the upper end of a hanger or supportsping 33. The lower end of each of these springs is connected to one of the lugs 33.

pair of oppositely disposed.

It wm benoted that there are two support I springs 39 provided for each of the brake elements I2v and I3 and that the ends of the arms 31 are so located with respect to said brake elements that the springs 33 are inclined outwardly slightly from the wheel sothat the action of gravity on said elements'will effect movement of the brake elements from the wheel 4 to their release positions. shown in the drawings.

I'he hanger springs 33 are provided to resiliently support thebrake elements`I2 and I3 from the journal bearing 3, which is an unsprung part of the truck, and to act through said elements and the bars' 3l and 32 connected to the brake element I4 for supporting the same in its release position, as shown in the drawings. It will be noted that the space between the arms 31 adjacent the dead brake lever I3 provides for operation of said lever between said arms.

The brake mechanism above described is wholly links 2l and 23 as will now be evident, and its operation may be controlled by apparatus which will now be. described.

'I'he upper end of the live brake lever 24 is pivotally connected by a pin 40 to one end oi' a link 4I the opposite end oi' which is provided with an opening through which extends one end of a brake lever 42. This lever may extend through a suitable opening in the side piece 6 of the truck frame wherein its may be pivotally connected to said side piece by a pin 43.y The opposite end of the brake lever 42 is connected to a piston rod 44 of a brake cylinder device 43 which may be mounted on any suitable part of the truck such as against the inner face of the side piece 6 of the truck frame.

The brake cylinder device 45 comprises a piston 46 having at one side a pressure chamber 41 andv at the opposite side a non-pressure chamber 43 through which the piston rod 44 extends connecting the brake cylinder piston 46 to the brake lever`42. A release spring 49 provided in the nonpressure chamber 43 acts on the brake cylinder piston 46 for urging it to its release position shown in the drawings. The pressure chamber 41 is connected to a brake cylinder pipe through lwhich fluid under pressure is adapted to be supthrough the springs 39 from the journal bearing- 9 which is.unsprung and upon which the truck frame I is spring supported. kThe only .connections between the brake mechanism and the truck frame are through the link 2 I, which serves as an anchor for the upper end of the dead lever I8 through the torque arm 28 and the brake cylinder link 4I, butv it will be noted that these links and the torque arm are so arranged that forces applied thereto during braking, which will be later described, are adapted to act in' a generally horizontal direction so as to thereby not interfere to any material degree with free movement ofthe truck frame in a vertical direction relative to the brake mechanism.

Operation of the brake mechanism shown in Figs. 1 to 3 of the drawings With the several brake elements I2, I3 and I4 released from the tread of wheel 4 and supported from the journal bearing 9 by the springs 39, the truck wheel 4 is free to rotate, as will be evident.

If it is desired to eiect an application of the brakes on the Wheel k4, fluid under pressure is supplied through the pipe 50 to the pressure chamber 41 in the brake cylinder device 45. After this pressure becomes sufficient to overcome the pressure of the release spring 49 on the brake cylinder piston 46 it then moves said piston in the direction of the right hand and rocks the brake lever 42 in a clockwise Adirection and through the medium of link 4I effects rocking of the brake lever 24 in a counterclockwise direction, as viewed in Figs. 1 and 2.

This movement of the live brake lever 24 initially acts through the pin 25 to move the brake element I3 into engagement with the tread of the wheel 4 and through the tie rods 26 on the dead brake lever I8 to effect movement of the brake element I2 into engagement with the tread of said wheel at the opposite side thereof.

VSince the elements I2 and I3 are thus moved into engagement with the tread of wheel 4 below the horizontal center-line of said wheel, and also due to the fact that the line of force applied to said elements passes below the axis of the wheel 4, further pressure of the brake cylinder piston 46 applied to said brake elements forces said elements downwardly around the wheel toward each other. This downward movement of the brake elements `I2 and I3 acts through the bars 3l and 32 on the pin 21 to effect movement of the brake element I4 in a downwardly direc- 4tion into engagement Wit-h vthe top portion of wheel 4, such movement of the several brake ele` ments into engagement with the wheel being opposed by the support springs 39, which however are extensible to provide for such operation.

After the brake element I4 is moved into contact with the wheel `4 it is pulled against said wheelfwith a force equal to the combined downward pull of theclasp arranged brake elements I2 and I3 on the bars 3| and 32 and thus provides braking of the wheel which is in addition to that provided by the brake elements I2 and I3.

It will be noted that the force applied to the brake element I4 through the bars 3l and 32 from Ythe brake elements I2 and I3 is a component of the actuating force applied by the brake cylinder piston 46 to the elements I2 and I3 due to the elements I2 and I3 being located below the horizontal center-line of the wheel and also due to the direction of action of the force applied to the elements I2 and I3. The degree of pressure between the upper brake element I4 and the wheel therefor depends upon the downward pull o1.' the brake-elements I2 and I3, whereas the degree of braking effected by the elements I2 and I3 depends upon the pressure of fluid supplied to act on the brake cylinder piston 46. The degree of braking obtained on the wheel 4 is therefore equal to the sum of the braking effects of each of the several brake elements and may be varied 'by varying the pressure of fluid supplied to act in the brake cylinder device, in the usual well known l manner.

When the brakes are applied, as just described, it will be evident that the weight o f the brake mechanism is entirely carried by the Wheel 4 independently of the truck frame; It will also be noted that the downward movement .of the several brake elements into engagement with the wheel actuates the link 2I 'and torque arm 23 to a substantially horizontal position so that force applied therethrough to the truck framewill have substantially no effect upon free vertical movement of the frame relative to the wheel 4Iwhile the brakes are applied.

The torque arm 29 acts when the'brakes are applied to hold the brake element I4 against turning with the wheel 4 and-since it thus anchors the upper end of the bars 3l and 32 the brake elements I2 and I3 are also secured thereby against rotation with the wheel.

When it is desired to eect a release of the brakes after an application, the fluid under pressure is vented from the brake cylinder piston chamber 41 by way of pipe 50 and when such pressure is reduced to a sufficientdegree, the release spring 49 acting on the brake cylinder piston 46 moves said piston back to its release position, shown in the drawings.

'I'hls movement of the brake cylinder piston 46 turns the brake lever 42 in a counterclockwise 75 direction which in turn effects movement of the upper end of the live brake lever 24 in a direction away from the Wheel 4. This operation of the live lever 24 acts to move the brake element I3 away from the wheel 4 and also acts through the tie rods 29 to operate the dead brake lever I9 to move the brake element I2 away from said Wheel. As the brake elements I2 and I3 are thus moved away from the wheel, the supporting springs 39 act to lift said elements back to their release position during which movement said springs also act through the bars 3l and 32 to lift the brake element I4 away from the wheel 4 and b ack to its release position, in which release positions said elements are adapted to be carried to provide for free rotation of the wheel 4 until a subsequent application of the brakes is eiected. g

After the several brake elements are thus returned to their release positions, it will be noted that said elements and the live and dead brake levers and the connecting bars 3I and 32 are again resiliently supported from the unsprung journal bearing 9.

It will now be evident that at no time is the truck frame I subjected to the weight of the brake mechanism so that said frame is capable of movement relative to the wheel 4 in a vertical direction independently of said mechanism at all times.

Description of the brake mechanism shown in Figs 4 to 7 of the drawings This embodiment of the invention is shown associated with a vehicle truck of the type having an equalizer bar 5I extending parallel to and disposed below the side frame 5 with the end of said equalizer bar supported directly on the top of the journal bearing 9. This equalizer bar supports a. spring 52 upon which the truck frame I is resiliently supported. This construction is so well known that a further description thereof is not deemed essential.

According to the invention, the equalizer bar 5I is provided at the side of wheel 4 adjacent the longitudinal center of the truck, with a support bracket 53 extending outwardly from the bar to a point in line with but spaced away from the tread of said wheel. In the outer end of this bracket there is provided a pivot pin 54 to.

which the upper end of a pair of hangers 55 are pivotally connected. The lower ends'of these hangers are disposed at the opposite sid of the brake element I3 and are pivotally connected to the pin 25 secured in the flanges I1 of said brake element whereby said brake element is supported from the equalizer bar 5I, which is an unsprung part of a vehicle truck.

The equalizer bar 5I is provided with an extension 56 which projects in the direction of the end piece 6 of the truck frame and past the tread of the wheel 4 where it is provided with an outturned bracket 51 similar to but disposed opposite to the bracket 53. The`bracket 51 is provided with a pivot pin 59 upon which is mounted the upper ends of a pair of hangers 59 the lower ends of which are disposed at opposite sides of the brake element I2 and are pivotally connected to the pin I9 secured in the flanges I1 of said brake element. The brake element I2 is thus also supported through the medium of hangers 59 from the equalizer bar 5I which is an unsprung portion of the vehicle truck.

It will be noted that thepivotal connections amacoi between the hangers 55 and 59 and the equalizer bar 5I are so arranged with respectto the brake elements I2 and I3 that the action of gravity on said elements is adapted to eilectmovement thereof in a direction away from the tread of the wheel 4.

A dead lever 59 is provided adjacent the outer face of each of the hangers 59, the two dead levers having their lower ends i'ulcrumed on pin I9 secured in the brake element I2 and their upper ends pivotally connected by a pin 5I to one end of each o! a pair of links 92 the opposite ends of which are pivotally connected to a pin 63 secured in an upstanding portion 94 oi' the bracket 51 which projects outwardly from the equalizer bar 5I. At the opposite side of the wheel 4 there are provided a pair of oppositely disposed, like, live brake levers 95 pivotally connected at their lower ends to the pin 25 in the brake element I3 and at the opposite sides thereof. The upper ends of the two live brake levers 95 are pivotally connected to the opposite ends of a T-shaped head 96 of a tension rod 91.

The brake element I4 located above the wheel is provided with a pivot pin 21 to which one end of a torque element 29 is connected, as hereinbe- Iore described in connection with the structure shown in Figs. 1 to 3 oi' the drawings. 'Ihe opposite end of this torque element 29 is connected to a pin 29 which is secured in an upstanding portion 69 of the bracket 53 projecting from the equalizer bar 5 I At each of the opposite sides of the brake element I4 and wheel 5 there is provided a depending link 19. The upper ends oi' the two links 19 are pivotally connected to the pin 21, while to the lower end of each oi' said links there is pivotally connected by pins 13'and 14, respectively, the upper ends of two oppositely disposed dia"- onally extending links 1I and 12; one set 'f links 19, 1I and 12 being provided at each si e of the wheel 4, as clearly shown in the drawings. The opposite or lower end of the link 1I at each side of wheel 4 is pivotally connected by a pin 15 to the adjacent dead brake lever 99 above the connection thereof with the brake element I2, while the opposite and lower end of the link 12 at eachv side oi' wheel 4 is connected by a pin 15 to the adjacent live brake lever 65 above the connection with the brake element I3.

The links 19, 1I and 12 at each side of wheel 4 constitute a toggle the opposite ends of which are connected to the dead and live brake levrs 99 and 95, while the knee of each toggle is cx :finected through the pin21 to the brake elemc t I4 disposed above the wheel 4.

Depending from the bracket 53 is a lug 19 ai d screw-threaded into this lug in line with 'he outer edges of the two hangers 55 are a pair of adjusting screws 19.

A pair of like screws 99 are provided in a lug 9| depending fromthe'bracket 51 and in line with the outer edges of the hangers 59. The adjusting screws 19 and 99 are provided for engagement with the hangers 95 and 59, respectively, upon movement oi the brake elements I2 and I3 away from the tread of wheel 4 to denne the clearance space between said elements and tread, and by proper adjustment of' said screws said clearance space may be adjusted to any desired degree. A lock nut 92 is provided on earh of the screws 19 and 99 for securing said scre in an adjusted position.

The operation of the brake mechanism sl .n in Figs. 4 to 7 of the drawings is adapted 1 Je controlled through the tension rod 81 which is provided in the end opposite the T-shaped head 88 with a socket in which there is disposed to operates. ball'88 which is provided on one end of abrake lever 84. 'I'his lever may extend in a direction transversely of the truck through a suitable opening in the side piece 8 wherein it may be pivotally connected to said side piece by' a pin 86. The other end of brake lever 84 is pivotally connected to the piston rod 44 of the brake cylinder device 48 which may be secured to theinside of the side piece of the truck frame. The brake cylinder device 48 may be of the same construction as that shown in Fig. 1 of the drawings, comprising a brake cylinder piston 48 havingat one side a pressure chamber 41 connected to a pipe 50 and having at the opposite side a non-'pressure chamber 48 through which the. piston rod 44 connected to the piston 48 extends, and which contains a release spring 48 for urging the brake cylinder piston to its release position in which it is shown in the drawings.

Operation of lthe brake mechanism shown in Figs. 4 to 7 of the drawings Assume that the several parts of the brake mechanism are in their release position, as shown in the drawings, in which position the brake eleunder pressure is supplied through the pipe 50 lrection as viewed in the drawings.

to the pressure chamber 41 in the brake cylinder device and therein acts on the brake cylinder piston 48 to effect movement thereof in the di-l rection of the left hand to thereby rock the brake lever 84 in a counterclockwise direction about its pivot 86, as viewed in Fig. 4 of the drawings. This movement of the brake lever 84 is transmitted through the rod 61 to the live brake levers 65 and acts to rock said levers in a clockwise di- The initial rocking movement of the live levers 65 is about the pin 25 carrying the brake element I3 and thus acts to move the pins 16 connected to the toggle links 12 away from the pins 15 connected to the toggle links 1I. As the ends of the toggle links 12 and 1I are thus moved apart the brake element I4 is lowered by gravity into engagement with the tread of the wheel 4 and then acts to prevent further downward movement of the toggle pins 13'and 14 provided at the knees of thai toggles.

After the brake element I4 isthus lowered into engagement with the tread of the wheel 4 the pins 16 at the one end of the toggle links 12 become the fulcrums for the live levers 85 so that further rocking movement of said levers in a clockwise direction rocks the hangers 58 about the pivot pin 54 in such a direction as to move the brake element I3 into engagement with the wheel 4. After the brake element I3 is moved into contact with the wheel the pivot pin 25 again becomes the fulcrum for the live levers 85 so that further movement of said levers by continued operation of the brake cylinder device then acts through the toggle links 12, and 1Iand the c onnecting pins, on the pins connecting the links 1i to the dead levers 60. The force thus applied to the pins 15 then rocks the dead levers 60 about their fulcrum connections with the bracket 84 through the links 82 in such a direction as to swing the hangers 59 toward the wheel 4 for thereby moving the brake element n into engagement with the treed er said wheel.

After the brake elements I2, I3 and i4are thus all moved into contact with wheel 4 the pressure applied by the brake -cylinderpiston 48 to the live levers 8l acts through the toggle links 12,

1I and 1I to force the several brake "elements into braking engagement with the tread of the "wheel 4 to effect braking thereof. The degree of n win be evident that the pressure with whichP the brake element I8 is forced against the wheel` is governed by the moment arms of 'the live levers 88 at either side of the pins 18. Substantially the same degree of pressure as applied to the pins 18 kfor forcing 7the brake element I8 into engagement with the wheel is transmitted through the toggle links 12, 10 and 1I to the pins 18 for operating the dead levers 88 to force the brake element I2 into engagement with the wheel, and assuming that the movement arms of said dead levers are the same as of the live levers, the brake element I2 will be forced into engage-y ment with the wheel with the same degree of force as the brake element I3.r In other Words, the toggle transmits -substantially the same pressure for operating the brake lelement I2 as provided for operating the brake element I3.

The vertical component of the pressure applied to the opposite ends of toggle links 12 and 1I is transmitted through the links 10 to the pin 21 for forcing thev brake element I4 into braking engagement with the top of the wheel 4. `This component of force of course depends upon the angularity of the oppositely disposed toggle links 12 and 1|, the same as inany toggle mechanism. TheV angularity of lthe particular construction shown in the drawings is governed mainly by the length of the links 10 which however may be such as to provide any desired degree of braking of the brake element I4. The length of the links 10 may if desired be such as to obtain the same degree of braking from the element I4 as obtained from the elements I2 and I3, assuming thatA the brake mechanism is so varranged that both of the elements I2 and I3` brake equally.l It will of course be understood that the. degree of braking provided by the brake element I4 is a function of the angle between the toggle links 1I and 12.

Due to the fact that'the clasp brake elements I2 and I3 engage the wheel 4be1ow the horizontal center-line thereof, and also to the fact that the actua-ting force applied to said elements acts in a directionan extension of which is disposed below the axis of wheel 4, said clasp brake elements tend to be forced downwardly around the wheel in effecting an application of the brakes in the same manner as occurs in conventional type of brake rigging and which in conventional type of brake rigging! results in areduction of the effectiveness of the brakes for a certain actuating pressure. Such downward movement of the clasp brake elements I2 and I3 is however prevented in the present construction since the brake element I4 acts through the toggle links 18, 1I and 12 to support the clasp brake element-s I2 and I3 in substantially the same position relative tothe wheel- 4 as obtained upon initial engagement with said wheel. A certain degree of the downward pull of the clasp brake elements I2 and I3 during braking may be `reductionin effectiveness of the brake elements I2 and' I3 due to their movement downwardly around th'e wheel 4 is onset by and acts to increase the enectlveness of the brake element -I4 and is not thus lost insofar as actual braking is concerned as occurs in conventional types of brake riggings. I

When. the brakes are applied the torque arm 28 acts to hold the brake element I4 against rotative movement with the wheelV 4 and acting through the toggle links 10, 1I and 12 also holds the brake elements I2 and I3 against turning with the wheel 4, as will be apparent. The hangers 55 and 59 also act to accomplish` this same end, but when the brake elements are in braking engagement with the wheel 4, said hangers serve no useful purpose. 'I'he .only function oi' the hangers is to support the brake elements when the brakes are released, as will now be described. v

In order to eilect a release of the brakes after of the invention it will be noted that the Summary i above described embodiments bnke In bother the ,mechanisms are compactly arrangedimmediatean application the iluid under pressure is released from the brake cylinder pressure chamber 41, and when said pressure is reduced sumciently, the release spring 49 acts to move the brake cylinder piston 45 back to its release position as shown in the drawing. 'Ihis movement of the brake cylinder piston acts through the push rod 44, brake lever 84 and link 61 to rst release pressure on the brake mechanism and to then rock the live brake levers 85 in a clockwise direction back to their release position shown in the drawings.

As they uve levers ss are Vthus moved the clasp brake elements I2'and I3 swing away from the wheel 4 due to the action of gravity until the hangers 55 and 59 engage the adjusting screws 19 and 80, respectively, which denne the release positions of said elements.

After the brake elements I2 and I3 are thus moved to their release positions, further release movement of tho live levers 65 by the brake cylinder release spring 49 moving the brake cylinder piston back to its releasel position actsr through the toggle links 12, 1I and 1D to elevate the brake element I4 to its release position disengaged from the wheel 4, as shown in the drawings, said position being obtained upon comple,- tion of the release movement of the brake cylinder piston. 'I'he wheel 4 is now free to rotate.

From the above description oi the parts and operation of the second embodiment of the invention it will be evident that the support and operation of the brake mechanism is independent of the truck frame I, except for the connections through the anchor links 62 for the dead levers 50, the torque arm 28 for the brake element I4 and the brake cylinder connecting link 61, but these connections are so arranged that any force applied to the truck frame when the brakes are applied acts in a substantially horizontal direction so as to thereby not eifect to any material degree the springing or free vertical movement of the truck frame with respect to the truck wheel 4 and it will also be evident that such movement and the vertical position of the truck frame I with respect to the truck wheel 4 will have substantially no effect upon the posi'- tioning and operation of the brake elements.

vbrake mechanism shown in Figs, 1

ly. around l,the rotatingmember to be braked and are supported directly from unsprung parts of the ,vehicletruch due to which the vertical positioning or vertical movement oi' the truck frame has substantially no e'ect upon the positioning and operation .of the brake mechanisms and, conversely, the -brakem at no time have any material eii'ect upon the springing of thetruck frame. Due to these novel arrangements the spacing of the brakeelements I4 above the vwheel can be` made whatever degree is desired and will Vnever -be iniluenced by vertical movement of the truck trame, and as a consequence the clearancebetween the clasp ar-4 ranged shoes I2 and I3 can also be ilxed at any desired degree, which would be impossible were these elements carried by and movable with said frame.

In conventional truck design the brake rigging is usually carried by thei truck frame or some other sprung portion of the truck in order to maintain the dead or unsprungweight of the truck to as low a degree as possible. The equivalent. of this is obtained, as will be evident, in the to 3 of the drawings, since therein said mechanism is carried by the hanger springs 39 so that in this structure the dead orunsprung weight oi' the vehicle need be no greater than in conventional truck d'ign.` However, it is desired to point out that even iri-'this.embodiment the positioning and operation o! the brake mechanism is entirely free of the truck i'rame I so that neither will have I any adverse effect upon "the other.

'face, saidbrake mechanism comprising at least three brake" elements arranged around said surface in'spacedvrelation with respect to each other and adapted to be'jmoved into and out of braking engagement with surfaceV for controlling braking oi' sai'dmztigueksl actuating means for controlling the 'operati 'n of said brake elements, and spring means ,carried'by-an unsprung part of said truck and connected' to said brake elements for resiliently supporting'same independently of the sprung parts of. said truck.

2. A brake mechanism for a railway vehicle truck having, sprung and unsprung parts and a rotatable member included in said unsprung parts and provided with an annular braking surface, said brake mechanism comprising at least three brake elements arranged around said surface in spaced relation with respect to 'each other and adapted to be moved .into and out of braking engagement with said surface for controlling braking-of said "truck, actuating means for controllingV the operation of said brake elements, support means carried by an unsprung part of said truck and connected to said brake elements parts of said truck, and means independent oi aars-,co1

said support means providing a substantially horizontally acting connection between said brake mechanism and truck for securing said brake mechanism against rotation with said rotatable member.

3. A brake mechanism for a railway vehicle truck` having sprung and unsprung parts and a rotatable member included in s'aid unsprung parts and provided with an annular braking surface, said brake mechanism comprising at least three brake elements arranged around said surface in spaced relation with respect to each other and adapted to be moved into and out of braking engagement with said surface for controlling braking of said truck, actuating means for controlling i the operation of said brake elements, support l means carried by an unsprung part of said truck and connected to said brake elements for supporting same independently of the sprung parts of said truck, and means independent of said support means providing a substantially horizontally acting connection between said brake mechanism and a sprung part of said truck for securing said brake mechanism against rotation with said rotatable member. i

4. A brake mechanism for a railway vehicle truck having sprung and unsprung parts and a rotatable member included in said unsprung parts and provided with anannular braking surface, said brake mechanism comprising at least three brake elements arranged around said surface in spaced relation with respect to eachother and adapted to be moved into and out of braking engagement with said surface for controlling braking of said truck, actuating means for controlling the operation of said brake elements, support means carried by an unsprung part of said truck and connected to said brake elements for supporting same independently of the sprung parts of said truck. and means independent of said support means providing a substantially horizontally acting connection between said brake mechanism and an unsprung part of said truck for securing said brake mechanism against rotation with said rotatable member.

5. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism compr1s, ing at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, resilient hanger means carried by an unsprung part of said truck and connected to said two brake elements for resiliently supporting same independently of said truck frame, means carried by said two brake elements for supporting said third brake element, and actuating means for controlling the braking operation of said brake elements. v

6.'A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, resilient hanger means carried by an unsprung part of said truck and connected to said two brake elements for supporting same independently of said truck frame, means for actuating said two brake elements for braking said assembly, and means for supporting said third brakev element from said hanger means and operative to actuate said third brake element to brake said assembly upon operation' of said two brake elements to brake said assembly.

'1. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, a resilient hanger for resiliently supporting each of said two brake elements kindependently of said. truck frame, the two hangers being disposed at opposite sides of said assembly and being supported by an unsprung part of said truck, means carried by said hangers for supporting the third brake element, and means for controlling the operation of said brake elements to brake said assembly.

8. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, said truck having an unsprung part carried by said assembly, a spring at each of the opposite sides of said assembly carried by said unsprung part and supporting the brake element at that side of said assembly independently of said truck frame, means carried by the two springs for supporting said third brake element, and means for controlling the operation of said brake elements to brake said assembly.

9. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereofi hanger means carried by an unsprung part of said truck and connected to said two brake elements for supporting same in dependently of said truck frame, means for actuating said two brake elements for breaking said assembly, and rigid link-line means connecting said two brake elements to said third brake element for normally supporting said third brake element independently of said frame and for actuating said third brake element to brake said assembly upon operation of said two brake elements to brake said assembly.

10. A( brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are. arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, a dead brake lever operatively connected to one of said two brake elements, a live brake lever operatively connected to the other oi' said-two brake elements, an unsprung member carried by said assembly, hanger means carried by said unsprung member for supporting said two brake elements and said levers, supporting and actuating means for said third brake element connected to said levers for supporting said third brake element from said hanger means. and means for operating said levers and support and actuating means to effect movement of all of said 10 brake elements in the direction of said assembly Ivor effecting braking thereof.

. 11.'A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of 1s movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged go above said assembly on the vertical` center-line thereof, an actuating element operatively connected to each of said two brake elements, an unsprung member carried by said assembly, resilient hanger means carried by said unsprung member gs for resiliently supporting said two brake elements and the two actuating elements, support means connecting said third brake element to said actuating elements for normally supporting said third brake element from said hanger means, and so means for operating said actuating elements and support means to eil'ect movement of all of said brake elements in a direction to effect braking of said assembly.

12. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements. two of which g, are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, a dead brake lever operatively connected to one of said two brake elements, a live brake a lever operatively connected -to the other of said two brake elements, an unsprung member carried by said assembly, Ahanger means carried by said unsprung member for supporting said two brake elements and said levers, a tOgsle mechanism operatively connected at its opposite ends to said levers and at its knee to said third brake element for normally supporting said third brake element from said hanger means, and means for operating said levers and toggle mechanism to effect movement of all of said brake elements in the direction of said assembly to effect braking thereof.

13. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a 00 truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said brake mechanism comprising at least three friction brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, a dead brake lever operatively connected to one of said two brake elements, a live brake lever operatively connected to the other of said two brake elements, an unsprung member carried by said assembly, hanger means carried by said unsprung member for supporting said two brake elements and said levers, support and actuating means for said third brake element oonnected to said levers for supporting said third brake element from said hanger means, said dead lever having a fulcrum connection with-said unsprung member, and a brake cylinder device carried by said frame and connected to said live lever for eifecting the operation of both of said levers I and said support and actuating means to-eil'ect movement of all of said brake elements in the direction of said assembly for braking same, the connection between said brake cylinder device and live lever providing for vertical movement of l0 y said brake cylinder device relative to laid brake mechanism.

14. A brake mechanism for a wheel and axle assembly-of a railway vehicle truck having a truck frame carried by said assembly and capable 13 of movement relative to said assembly in a vertical direction, ,said mechanism comprising at least three brake elements two of which are arranged'at opposite sides of said assembly in clasp relation and the third of which is arranged above 20 said assembly on the vertival center-line thereof, an unsprung member carried by said assembly, means carried by said unsprung member and connected to said two brake elements for supporting same independently of said truck frame, live and dead brake levers operatively connected tovsaid two brake elements for effecting operation thereof to brake 'said assembly, means connecting said .third brake element to said two brake elements for supporting said third brake element and for $0 effecting operation of said third brakel element to brake said assembly upon braldng operation of said two brake elements, said dead lever having a fulcrum connection with said truck frame providing for movement of said frame relative to said 35 dead lever in a vertical direction, and a substantially horizontally acting torque member connected at one end to said frame and at the oppo- 'site end to said third brake element for holding said brake mechanism against turning with said o assembly and providing for movement of said frame relative to said third brake element in a vertical direction.

15.`A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a u truck frame carried by said assembly and capable of movement relative to said assembly in a vertical direction, said mechanism comprising at least v three brake elements two of which are arrranged at opposite sides of said assembly in clasp relan tion and the third of which is arranged above said assembly on the vertical center-line thereof, an unsprung member carried by said assembly, means carried by said unsprung member and connected to said two brake elements for supporting g5 same independently of said truck frame, live and dead brake levers operatively connected to said two brake elements for effecting operation thereof to brake said assembly, means connecting said third brake element to said two brake elements 00 for supporting said third brake element and for eecting operation of said -third brake element to brake said assembly upon braking operation of said two brake elements, said dead'lever having a fulcrum connection with said unsprung 05 member, and a substantially horizontally acting torque member connecting said third brake element with said unsprung member operative to hold said brake mechanism against rotation with ysaid assembly and providing for movement of 70 said frame relativev to said third brake'element in a vertical direction.

16. A brake mechanism for a wheel and axle assembly oi a railway vehicle truck having a journal bearing for saidaxle and truck frame u resiliently supported from said bearing and capable of movement relative to said assembly in a vertical direction, said mechanism comprising at least three brake elements two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, actuating means, operatively connecting said brake elements together for controlling the operation thereof to brake said assembly, means for controllingthe operation of said actuating means, resilient means carried by said journal bearing and operative independently of said frame for supporting said brake elements and actuating means and means connecting said brake mechanism to said frame and operative in a substantially horizontal direction to secure said brake mechanism against rotation with said assembly during braking thereof.

l'I. A brake mechanism for a assembly journal bearing for said axle and a truck frame resiliently supported from said bearing and capable of movement relative to said assembly ln a vertical direction, said mechanism comprising at least three brake elements two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, resilient means carried by said journal bearing for supporting said two brake elements independently of said frame, support and actuating means connecting said two brake elements to said third brake element for supporting said third brake element, means connected to said two brake elements for effecting operation thereof to brake said assembly and for also eifecting operation of wheel and axle said support and actuating means to effect operation of said third brake element to also brake said assembly and means connecting said third brake element to said frame and operative in a substantially horizontal direction during braking to hold said mechanism against rotation with said assembly.

18. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a journal bearing for said axle and a truck frame resiliently supported from said bearing and capable of movement relative to said assembly in a vertical direction, said mechanism comprising at least three brake elements two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, actuating .means operatively connecting said brake elements together for controlling the operation thereof to brake said assembly, means for controlling the operation of said actuating means, bracket-like means rigidly secured to and movable with said journal bearing, and hanger means carried by said bracket-like means supporting said brake elements and actuating means independently of said truck frame.

19. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a journal bearing for said axle and a truck frame resiliently supported from said bearing and capable of movement relative to said assembly in a vertical direction. said mechanism comprising at least three brake elements two of which are arranged at opposite sides of said assembly in clasp relation and the third of which .is arranged above said assembly on the vertical center-line thereof, actuating means operatively connecting said brake elements together for conof a` railway vehicle truck having a-v trolling the operation thereof to brake said assembly, means for controlling the operation of said actuating means, bracket-like means rigidly secured to and movable with said Journal bearing, and spring means carried by said bracket-like means supporting said brake elements and actuating means independently of said truck Lframe.

20. AA brake mechanism for a wheel and axle assembly of a railway vehicle truck having a Journal bearing for said axle, atruck frame capable of movement vertically relative to said assembly, and an equalizer able with said journal bearing and supporting said truck frame, said mechanism comprising atleast' three brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, actuating means operatively connecting said brake elements together for controlling the braking operation thereof, means for controlling the operation of said actuating means, and hanger means connected to and carried by said equalizer bar for supporting said brake elements and actuating means independently of said truck frame.

21. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a journal bearing for said axle, a truck frame capable of movement vertically relative to said assembly, and an equalizer bar carried by and movable with said journal bearing and supporting said truck frame, said mechanism comprising at least three brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, actuating means operatively connecting said brake elements together for controlling the braking operation thereof, means for controlling the operation of said actuating means, and a hanger at each side of said assembly connected to said equalizer bar and to the clasp brake element at said side of said assembly, the two hangers supporting all of said brake elements and with actuating means independently of said truck frame.

22. A brake mechanism for a wheel and axle assembly of a railway vehicle truck having a journal bearing for said axle, a truck frame capable of movement vertically relative to said assembly, and an equalizer bar carried by and movable with said journal bearing and supporting said truck frame, said mechanism comprising at least three brake elements, two of which are arranged at opposite sides of said assembly in clasp relation and the third of which is arranged above said assembly on the vertical center-line thereof, hanger means supported by said equalizer bar and connected to said two brake elements for supporting same independently of said truck frame, means for actuating said two brake elements for braking said assembly, and means connecting said two brake elements to said third brake element for normally supporting same and operative upon braking operation of said two brake elements to eiect operation of said third brake element to also brake said assembly.

23. A brake mechanism. for afwheel and axle .assembly of a railway vehicle truck having a journal bearing for said axle, a truck frame capable of movement vertically relative to said assembly, and an equalizer bar carried by and movable with said journal bearing and supporting said truck frame, said mechanism comprising at least three brake elements, two of which are arranged at opposite sides of said ly in bar carried by and movvclasp relation and the third o'f which is arranged ranged at opposite sides of said assembly in clasp above said assembly on the vertical. center-line thereof, live and dead brake levers connected to said two brake elements for controlling the brakling operation thereof,' hanger means suppOrted by said equalizer bar carrying said two brake elements and said leve'rs independently of said frame, and means operatively connecting said third brake element to said hangers and levers for supporting same and for effecting braking operation of said third brake element upon braking. operationof saidtwo brake elements.

24. Av brake mechanism for a wheel and axle assembly of a railway vehicle truck having a journal bearing for said axle, a truck frame capable of movement vertically relative to said as- I sembly, and an equalizer bar carried by and movable with said journal bearing and supporting said truck frame, said mechanism comprising at least three brake elements, two of whichMarevarrelation and the third of which is arranged above said assembly on the vertical center-line thereof,

IIlive and dead brake levers connected to said two brake elements for controlling the braking operation thereof, hanger means supported =by said equalizer bar carrying said two brake elements and said levers independently of said frame, and means operatively connecting said third brake element to said hangers and levers for supporting same and for eecting braking operation of said third brake element upon braking operation of said two brake elements, said dead lever having a fulcrum connection with said equalizer bar, and means providing a torque connection between said brake mechanism and equalizer bar for holding said brake elements against rotation with said assembly.

' RALPH T. WHITNEY.

t CERTIFIoATE oF'coRREcTIoN'. l Patent. No. 2,218,601. october 22, 191m.

" RALPH T. WHITNEY.-

It `1a lllexte'by certified that error appears in the printed specification ofthe ali'ove numbered patent' 'requringcorrection as follows: Page 9, second comm, line im', alom 21', for the word "with" read said-; and that the Asaid Letters Patent' should be read with this correction therein that the same may conform to the record of .the case in 'the Patent Office.

Signed and' sealed this 10th day of December, A. D4. 1914.0.

v v"Henry Van Arsdale,

(Seal) Actngcommiseoner of Patents. 

